Positioning device for grinding machines



A il 6, 1926. 1,579,713

' C. KNOWLES POSITIONING DEVICE FOR GRINDING MACHINES Filed July 15, 192$ ATTORNEYS.

Patented Apr. 6, 1926.

; UNITED STATES PATENT OFFICE.

CARROLL KNOWLES, OF HARTFORD, CONNECTICUT, ASSIGNOR TO PRATT & WHITNEY COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

POSITIONING DEVICE FOR GRINDING MACHINES.

Applieation iiled July 13, 1923. Serial No. 651,402.

To all whom it may concern:

Be it known that I, CARnoLL'KNowLEs, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Positioning Devices for Grinding Machines, of

Y which the following is a specification.

This invention relates to grinding machines and particularly to a positioning device adapted to be used in connection therewith to maintain the abrasive surface of the grinding wheel in a predetermined position.

An object of the present invention is to so mount the positioning device that the part contacting with the abrasive wheel, which is "usually a diamond, may be moved relatively to the abrasive surface to engage the ,wheel upon slightly different parts of its surface. The invention is particularly adapted for'use on a gear tooth grinder and will be described in connection with a machine of that type.

In gear grinders such .as shown in the patents to Maag 1,183,020 and 1,228,798, positioning devices are disclosed adapted to be moved periodically toward the work engaging surface of the wheel; As the sur-' face of the abrasive'wheel becomes worn away, means may be actuated by the wheel contacting means to positively advance the wheel sufliciently to compensate for the amount worn away. Preferably, this contacting member which forms part of the positioning device oscillatesand, as soon as the amount of wear on the wheel permits the member to oscillate up to or beyond a predetermined point, the wheel adjusting means is put into operation to compensate for the wearwhi'ch has taken place.

Usually, a diamond is used in connection with these positioning devices as the contacting member, the diamond being chosen on account of its great hardness and wear resisting qualities. The diamond, however, is subject to unavoidable slight Wear due to its being placed periodically in contact with the rapidly rotating abrasive wheel and it is to provide means to compensate for any wear on this diamond, or other contacting member. which forms the principal object of this invention.

In the present instance, the wheel er gages the work upon a very narrow active face,

this annular face being radial or normal to the axis of rotation of the wheel. The diamondengaging this narrow operative face of the wheel is made of considerably greater width than the width of this abrasive surface so that it may engage the active parts of the wheel upon a portion only of its surface. The diamond and other parts of the positioning device are therefore mounted on a slide preferably carried upon the same slide or head as the wheel spindle and wheel head. By slightly varying the position of this slide relative to the abrasive surface of the wheel, the diamond, or other contacting member, may be made to engage the wheel upon any portion ofits surface.

Also, as the wheel constantly wears away and is reduced in diameter, the position of the wheel and its spindle must be varied from time to. time relative to the work. 1 therefore provide means to move the positioning device and the contacting device thereof simultaneously with the movement of the wheel and wheel spindle. The movement of this ositioningdevice is so regulated that as t e wheel is uniformly reduced indiameter, the diamond is moved slightly relative to the active abrasive face of the wheel. In this way, the entire surface of the tributes the wear over its entire surface.

\Vith these and other objects in view, my invention consists in the features of construction and operation set forth in the following specification and illustrated in the accompanying drawing.

In the accompanying drawing annexed hereto and forming a part of this specification, I have shown my invention embodied in a gear tooth grinding machine but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawing:

Figure 1 is a front elevation of a portion of a gear tooth grinding machine having the present invention applied thereto.

Fig. 2 is a plan view of the gearing for moving the wheel head and the slide carrying the positioning device.

Fig. 3 is a detail showing an enlarged view of the operative surface of the abrasive wheel and the contacting member of the positioning device, and

Fig. 1 is a detail showing the different relative positions of the wheel and contact member in different positions of adjustment.

In the above mentioned drawing, I have shown but one embodiment of the invention which is now deemedpreferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly, my invention in its broadest as pect comprises the following principal parts: first, a gear grinding machine which may be of any toot-h generating type; second, means for supporting the work; third, a wheel head-carrying an abrasive wheel and adjustable toward or from the work; fourth, a wheel positioning device having a contacting member adapted to be periodically moved to engage the operative surface of the wheel; fifth, means supporting the positioning device so that it may be moved relative to the wheel hcadaand sixth, gearing disposed between the wheel head and slide carrying the positioning device permitting them to be moved at slightly different rates.

Referring more in detail to the figures of the drawing, a gear grinder of the type shown in the above mentioned patents to Maag is illustrated having a base 10 on which is mounted a suitable housing 11. The base 10 also carries a work support which, in the present instance, is movable laterally to effect. a rolling movement of the gear blank A and is also adapted to be traversed forward and rearward on ways 13 to feed the gear blank A past the wheel or wheels 14. As these mechanisms form no part of the present invention, they will not require further description. It is only necessary to state that means to index the gear blank A (not shown) are provided to present different teeth to the wheels.

On the housing 11 are ways 15 carrying two slides 16 which may be adjusted toward or from each other horizontally along the housing. These horizontally movable slides 16 carry slides 17 adjustable in an oblique direction on which are provided the wheel heads 18. A motor 19 on each of these obliquely adjustable slides 17 provides means for rotating its Wheel 14 about the inclined axis of the wheel spindle.

Slidably mounted on the wheel head carrying slides 17 are auxiliary. slides 20 having mounted thereon a major portion of the positioning device 21. The particular parts mounted on this slide 20 comprise the wheel contacting member 22 having a diamond 22 thereon and which, in the present instance, comprises as oscillating lever. Also, means are provided to periodically oscillate this lever 22 and energize an electric circuit by means of which the wheel adjusting means are actuated to compensate for the amount worn away.

This device 21 and slide 20 is mounted in ways extending exactly parallel to those upon. which the wheel head slide 17 is movable. It will therefore be seen that movement of the positioning device 21 will be parallel to the direction of movement of the wheel head 18 when the slide 20 is moved relatively to the slide 17.

Adjusting means are provided for the wheel head 18 and slide 17, these comprising a rotatable screw 25, the lower end of which may be rotatably mounted in the horizontally movable slide 16 and adapted to engage a nut 26 rotatably mounted in an extension to the slide 17. Rotation therefore of the screw 25 while the nut 26 remains stationary will effect inclined movement of the wheel head slide 17 and, as the positioning device 21 is mounted thereon. movement of this device will take place simultaneously with slide 17. Movement of the wheel head 18 in this manner will effect a movement of the positioning device 21 and its contacting member of exactly the same distance. This adjustment is made use of for setting the wheel relative to gear blanks of different diameter and may be readily accomplished by a crank placed on the squared end of screw 25.

As above described, however it is desirable to advance the positioning device 21 a slightly greater or less distance than the wheel 14 as the wheel is adjusted to compensate for its reduction in diameter. That is, with each adjustment of the slide 17 to compensate for wear of the wheel 14 the slide 21 and its'attached parts are moved slightly relatively thereto. In this way, other portions of the diamond forming a part of the contacting member 22 will be in contact with the operative surface of the wheel H as the wheel progressively wears away. I therefore connect a fixed screw 30 to the positioning device slide 20 and provide a nut 31 rotatable upon the upper end of this screw within a portion of the wheel bead slide 17. This nut 31 is provided with gear teeth 32 upon its periphery. The nut 26, by

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means of which the wheel head slide 17 itself is adjusted, is also provided with gear teeth 33. Between these two gears 32 and 33 is an intermediate or idler gear 34. The ratio of the above described gearing and the pitch of the screws 25 and 30 is such that the nut 31 engaging the positioning device screw 30 advances the positioning device 21 a slight distance more than the .wheel head is advanced with each adjusting movement I cause the contacting member 22 of the positioning device 21 to engage the active surface of the abrasive wheel 14 over its entire length as the wheel 14 is reduced from its maximum to its minimum diameter.

This will be clear from an examination of the diagrams in Fig. 4. When the wheel is first adjusted in position, it may engage the positioning device as shown at a and,'as the wheel is progressively adjusted to compensate for its'reduction, the member 22 engages it finally as shown at b. Thus any trifling wear upon the contacting member 22 will not affect the precision of axial adjustment of the wheel.

What I claim is:

1. A wheel positioning device for rinding machines comprising in combinatiom'a slide, a wheel head thereon having a rotatable abrasive wheel therein, means to adjust the position of said slide, and a slide carrying a wheel contacting device mounted on said wheel head carrying slide whereby said contacting device may be moved relative to and in a direction parallel to the direction of movement of said wheel head.

2. A wheel Positioning device for grinding machines comprising in combination, a slide, a wheel head thereon having a rotatable abrasive wheel therein, means to adjust the position of said slide in a direction 'sai per endiculanto the axis of rotation of wheel, and a slide carrying a wheel contacting device mounted on said wheel head carr ing slide and movable in a direction para lel to the direction of movement of the wheel head carrying slide whereby said contacting device may be moved in a direction parallel to the direction of movement of said wheel head.

3. A wheel positioning device for grinding machines comprising in combination, a slide, a wheel head thereon having a rotatable abrasive wheel therein, means to ad just the position of said head, a slide carrying a wheel contacting device mounted on said wheel head carrying slide whereby said contacting device may be moved relative to andin a direction parallel to the direction of movement of said wheel head, and means to adjust the positions of the wheel head and slide simultaneously.

1. A wheel positioning device for grinding machines comprising in combination, a slide, a wheel head thereon having a rotatable abrasive wheel therein and adapted to engage work upon a narrow annular surface, means to adjust the position of said head, a. slide carrying a wheel contacting device mounted on said wheel head carrying slide whereby said contacting device may be moved in a direction parallel to the direction of movement of said wheel head, and means to adjust the position of said contacting member so that the member may en age the abrasive surface of said wheel on 1(ii erent portions of the surface of the mem- 5. A wheel positioning device for. grinding machines comprising in combination, a.- slide, a wheel head thereon. having a rotatable abrasive wheel therein, means to adjust the position of said head, a slide carrying a .wheel contacting device of greater length than the width of the abrading surface of the wheel, and means whereby sa d contacting device may be moved in a direction parallel to the direction of movement of said wheel headrelative to movements of said wheel head. I

6. A wheel positioning device for grinding machines comprising-in combination, a wheel head having a rotatable abrasive wheel therein, means to adjust the position of said Wheel head, a slide carrying a wheel contacting device adj acent said wheel head, and

means to simultaneously move the wheel head and wheel contacting member slightly different amounts.

7. A wheel positioning device for grinding machines comprising in combination, a wheel head having a rotatable abrasive wheel therein, means to adjust the position of said wheel head, a slide carrying a wheel contacting device adjacent said Wheel head, and means to simultaneously move the wheel head and wheel contacting member slightly different amounts in the same direction.

8. A. wheel positioning device for grinding machines comprising in combination a wheel head having a rotatable abrasive wheel therein, means to adjust the position of said wheel head, a slide carrying a wheel contacting device adjacent said wheel head, and positive means to simultaneously move the wheel head and wheel contacting'member parallelly slightly different amounts in the .same' direction.

9. A wheel positioning device for grinding machines comprising in combination, a wheel head having a rotatable abrasive wheel therein, means to adjust the position of said wheel head, a slide carrying a wheel contacting device adjacent said wheel head, screw threaded means to move the wheel head and wheel contacting member, and geared means connecting said screw threaded means whereby said wheel head and contacting device may be adjusted slightly different amounts in the same direction.

10. A wheel positioning device for grinds ing machines comprising in combinat1o-n, a wheel head having a rotatable abrasive wheel therein, means to adjust the position of said wheel'head, a slide carrying a wheel contacting device adjacent said wheel head, and means to adjust the positions of said wheel headand contacting device equal -dis-.

tances simultaneously or to adjust said head and device unequal distances simultaneously in the same direction. I

11. A wheel positioning device for grinding machines comprising in combination, a wheel head having a rotatable abrasivie wheel therein, screw threaded means to adjust the position of said wheel head, a slide carrying a wheel contacting device adjacent said wheel, head, screw threaded means to adjust said slide, and means to move said' wheel head andcontacting device equal distances in the same direction simultaneously or to adjust said head and device unequal distances simultaneously in the same direc tion.

12. A wheel positioning device for grinding machines adapted to engage work upon a narrow annular surface comprising in combination, awheel head having a rotatable abrasive whee] therein, means to adjust the positionof said head and Wheel, a wheel contacting device mounted adjacent said wheel and adjustable relative thereto, said contacting member being adapted to engage said wheel upon a surface longer than the width of the abrasive surface of said wheel, and means to move said contacting device relative to the abrasive surface of said wheel.

13. A wheel positioning device for grinding machines adapted to engage work upon a narrow annular surface comprising .in-

combination, a wheel head having a rotatable abrasive wheel therein, means to adjust the position of said head and wheel, a. wheel contacting device mounted adjacent said wheel and adjustable relative thereto, said contacting member being adapted to engage said wheel upon a surface longer than the width of the abrasive surface of said wheel, and means connecting said wheel head and contacting device whereby said contacting device may be positively moved relative to the abrasive surface of said wheel.

In testimony whereof, I hereto aflix my signature.

' CARROLL KNOWLES. 

